Hello, all. Since things have been quiet lately, I thought I'd throw out
a few comments, suggestions, what-ifs, and how-abouts to provoke some
discussion.
One major issue that I've mentioned briefly to Eric is the divide between
language specification and implementation requirements. I think there a
few things that are "hard-wired" in the draft that needn't be, and
vice-versa.
My main source is the slightly-more-up-to-date w1631, part 4.
About the internal representation of a sample as double-precision float,
I know there was some discussion on this. Is this something that must be
part of the specification? For example, is it appropriate for the
MIDI-only profile?
--The "Sample Conversion" subsection was changed to include fracdelay, to distinguish efficient delays from less efficient, accurate, dynamic delays. It seems like the first time this distinction has been made: upsamp specifies linear interpolation, and the oscil family makes no mention of it whatsoever. Should we address band-limited interpolation?
"allpass" has a similar sort of inconsistency in the line, "The delay is specified in seconds and rounded to the nearest sample for implementation."
...the bigger point being that I can envision SAOL being used by a wide variety of users. Some are going to be mastering content for digital distribution, and therefore exacting about the sound quality. Others could be playing it through a mono speaker, and couldn't give a whit about a little foldover. --
The filter options seem a little limited. How about adding some FIR filter design table generators (a la MATLAB's sigproc)? A convolution opcode? A filter opcode (using two tables instead of serial biquads)?
I think all of these would get more use than Chebyshev Polynomials...
[as an aside, I think chebys are cool. But I also think that SAOL's design is a little too influenced by its academic heritage-- some meat-and-potato signal processing is left as an exercise to the student.] --
"ksig MIDIbend allows access to MIDI "pitchbend" information for this note." I believe pitchbend is typically by channel. Minor, niggling point. --
I welcome comments... in fact, I hope this stimulates some discussion...
Peace, adam
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= You can't spell "multimedia" without "time"... Adam T. Lindsay, Research Scientist phn: 32.2.721.5454 Riverland Research fax: 32.2.721.5380 adam@riv.be url: www.riv.be/research/ ...'cos it would be "muldia," and that makes no sense. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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